Extrusion device and process



Apl'll 1, 1952 L. GILLETT EXTRUSION DEVICE AND PROCESS Filed March 5, 1948 ivi.

INVENTOR Patented Apr. 1, 1952 UNHTED vSTATES PATENT OFFICE EXTRUSION DEVICE AND PROCESS Lewis L. Gillett, Endwell, N. Y., assigner to International Business Machines Corporation, New York, N. Y., a corporationV of New York Appiieauen March 3, 194s, serial No. 12,756

1 Claim. (Cl. 207-2) This invention pertains to contact brushes of the type used in electrical accounting machines and to a novel method for producing such articles.

It has been found that Contact brushes having multiple wires are superior to single strand brushes in most uses to which these articles are put in the electrical accounting machine art; consequently, contact brushes for use upon electrical accounting machines normally consist of one or more groups of tufts of metallic wires bound together at one end.

A common method for producing. these articles is by die casting a slug upon one end of a tuft of wires to bind them together. This method produces a reliable contact brush; however, the cost is considerably higher than that of similar articles manufactured by a machine of the type disclosed in U. S. Patent 2,350,515, wherein the wires of a group or tuft are bound together by a long ferrule crimped about them after their being inserted thereinto. In the present invention a still more economical product is produced by extruding a ductile ferrule about one end of a group of wires to bind them together to form a contact brush.

The principal object of this invention is to provide a means in the form of an extrusion die for producing contact brushes having one or more groups or tufts of wires .bound together at their ends by a metal portion extruded from a ferrule having a central bore.

A further object is to provide a process by which contact brushes may be made more economicaliy than by other presently known processes.

A still further object is to provide a process for making contact brushes at a rapid rate with a minimum number of operations as compared with other presently known methods.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 shows a cross section of a die for extruding a hollow ferrule of metal upon a group of wires at the beginniing of its operation cycle.

Fig. 2 shows a cross section of the die disclosed in Fig. 1 at the end of its operation cycle.

Fig. 3 illustrates one variety of wire tuft and hollow ferrule prior to being operated upon by the die of Fig. l.

Fig. 4 shows a ferrule and wire groups or tufts, together with inter-group spacers, prior to .being operated upon by a die having a rectangular cross y section.

Fig. 5 shows the product resulting from the arrangement of Fig. 3.

Fig. 6 illustrates the product resulting from the arrangement of Fig. 4. (The product in this instance is similar to that illustrated in Figs. 22, 29, and 30 of U. S. Patent 2,350,515).

Now referring to Fig. 1, a die 10, which may be in the form of an insert for a standard punch press, is provided with a coacting plunger I i. A tuft of wires I2 is placed in the die iii and located within a shedder I3 -to protrude at the top thereof and extend into an extension cavity I4 sufficiently to permit a ferrule I5 to be inserted over the protruding end. The lower ends of the wires abut a buffer I6 forming a member of the shedder I3 which is normally forced upward in its bearing I1 by a spring Iii. Means (not shown) such as a standard punch press ram is used to force the plunger II against the wires l2 and the ferrule I5 surrounding them, thereby extruding the ferrule I5 from the cavity i4 into the die proper to cause the metal composing the ferrule I5 to flow and seize the wires I2, as illustrated in Fig. 2.

The wires I2, see Fig. 3, may be steel piano wire or wire of a similar type, and the ferrule I5 is preferably of a ductile metal such as aluminum or copper. One form of the contact brush is shown in Fig. 5 where the wires I2 are bound into the extruded slug I9.

A modification of the contact brush shown in Fig. 5 may be obtained by providing the die ID with a rectangular rather than a circular cross section, the cavity I4 remaining unchanged, and placing spacers 20 between the wires I2, see Fig. 4. The spacers 20 are arranged to divide the wires I2 into groups, and the wires and spacers placed in the locating cavity of the shedder I3 in a prearranged fashion, the cross-section of the shedder cavity also being made proportionately rectangular. The process follows thereafter as heretofore described. After the ferrule is formed around the ends `of the wires I2 and the spacers 2 0, the resulting article is removed from the die, and the spacers 2i) are broken off at the points of their emergence from the slug 2l, resulting in a contact brush similar to that shown in Fig. 6. A divided contact brush of similar type may be produced wherein extruded metal from the ferrule I5 provides the spacers 20 by employing a shedder I3 provided with a pair of tongues (not shown).

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the in tention, therefore, to be limited only as indicated by the scope of the following claim.

What is claimed is:

A die for extruding a metallic ferrule to form a slug upon an end of a tuft of metallic larnents comprising a die body having a cavity projecting therethrough, the said cavity tapering at its one end to have a larger cross-section to hold a ferrule, a movable shedder slidable axially within the said cavity in its smaller cross-section, the said shedder having a longitudinal bore for positioning the said tuft therein. an abutment at one end of the said shedder and movable therewith, the said abutment contacting one end of the said CJI tuft to position it to extend beyond the other end of the said shedder, and a spring acting against the said abutment to bias the said shedder normally so that the protruding end of said tuft enters the said ferrule.

LEWIS L. GILLETT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,568,774 Scoeld Jan. 5, 1926 1,658,677 Hanna Feb. 7, 1928 1,934,652 Anderson Nov. 7, 1933 1,984,775 Swartz Dec. 18, 1934 2,350,515 Loungway June 6, 1944 2,530,669 Thornton et al Nov. 21, 1950 FOREIGN PATENTS Number Country Date 354,767 Great Britain Aug. 13, 1931 

